[0001] This invention relates to a medical laser probe for effecting incision or vaporisation
with respect to tissues of human or animal organisms and to a process for making a
medical laser probe. More specifically, the present invention pertains to a dual mode
laser surgical probe which achieves tissue vaporisation by the combined heating occasioned
by direct laser irradiation of the tissue as well as by heating of the laser tip which,
in turn, is brought into contact with the tissue in which the incision is being made.
[0002] Laser surgery of a non-contact variety has been known for many years. In general,
the simplest form of non-contact laser surgery utilises a flexible quartz fiber for
transmitting laser energy from a Nd:YAG laser source to the tissue undergoing treatment.
In this system, the end of the quartz fiber serves as the probe for irradiating the
tissue to effect incision or coagulation thereof. The fiber tip, however, must be
maintained in spaced relationship to the tissue to avoid fouling of the fiber and,
importantly, to avoid heat damage to the fiber end. Non-contact laser systems utilising
a laser transmissive member at the output end of the fiber to focus or otherwise alter
the radiation characteristics of the fiber have also been proposed, for example, by
Enderby, US Patent No. 4273109.
[0003] Such non-contact laser irradiation systems, however, exhibit poor operating efficiency
as well as poor reproducibility. In general, it is necessary to maintain a fixed spacing
between the output end of the laser probe or fiber and the tissue undergoing treatment
in order that the laser energy density at the tissue remains constant. However, in
the conventional non-contact laser irradiation system, it is difficult to keep the
distance constant, especially when the surgical procedure is being performed remotely
through use of an endoscope. In addition, the non-contact irradiation system exhibits
a significant disadvantage in that the laser beam is backscattered from the surface
of the tissue and a considerable percentage of the radiated laser energy is lost.
[0004] The inventor of the present invention has previously proposed an improved probe having
a tip member which is made, for example, of an artificial sapphire disposed in front
of an optical fiber through which the laser energy passes enroute the tissue undergoing
treatment. Thus, in WO 85/05262 there is disclosed a medical laser probe for conveying
laser energy from the output end of an optical laser waveguide to a tissue undergoing
laser treatment the probe comprising a laser transmissive material having a laser
energy input region for receiving laser energy from an optical waveguide and a laser
energy radiation surface, the laser energy from the input region being propagated
through the probe transmissive material to be incident on the probe radiation surface,
the probe radiation surface being in the form of a melt which contains bubbles such
that the melt is translucent to a degree of 20 to 50%. In view of the properties of
the tip member, in particular, its higher melting temperature, the probe can be maintained
in direct contact with the tissue with a corresponding improvement in procedure efficiency
and reproducibility.
[0005] This new contact laser irradiation system, however, still requires substantial output
from a laser generating unit, often in excess of 40 to 50 watts for incision or vaporization,
although the required output depends upon the mode of treatment. The necessitates
use of a large-scale laser generating unit, including its associated bulky power supply,
which is expensive and non-portable. The laser probe of the present invention produces
the required tissue heating at substantially reduced laser power levels.
[0006] WO-A-84/04879 describes a laser probe which comprises an infrared absorbing element
whereby the predetermined percentage of the laser energy which is converted into heat
is approximately 100%. The infrared absorbing element is covered with a coating of
laser transmissive material, which coating serves to provide for easy release from
the tissue and for mechanical protection of the element.
[0007] GB-A-2154761 discloses a diffusive optical fibre tip for surgical applications. Diffusion
is achieved by covering the fibre tip with a resin compound impregnated with fine
particulate powder so as to give a reflective or refractive effect.
[0008] According to the present invention there is provided a medical laser probe for conveying
energy from the output end of an optical laser waveguide to a tissue undergoing laser
treatment, the probe comprising laser transmissive material having a laser energy
input region for receiving laser energy from the optical waveguide and a laser energy
radiation surface, the laser energy from the input region being propagated through
the probe transmissive material to be incident on the probe radiation surface, characterised
in that an infrared absorbing coating is applied to and conforming with the laser
energy radiation surface for converting a predetermined percentage of the laser energy
incident thereon into heat energy, whereby the increased temperature of the probe
radiation surface will enhance tissue vaporisation and whereby the laser energy entering
the probe not converted to heat energy by the infrared absorbing coating irradiates
tissue adjacent the radiation surface.
[0009] More specifically a laser probe has its outside radiating surface covered with a
thin coating of infrared absorbing material such as manganese dioxide (MnO
2). The manganese dioxide absorbs some of the laser energy as it passes from the probe
thereby heating the tip region of the probe to, for example, about 700°C. When the
heated outer surface of the probe is brought into contact with the tissue, the tissue
adjacent thereto is carbonised due to the heat. Thus, vaporisation of the surface
tissue is significantly enhanced. However, as noted, all of the laser energy is not
absorbed by the infrared absorbing material and a part of the laser beam is passed
directly to the tissue. The direct irradiation of the tissue enhances the vaporisation
of the carbonised tissue as it passes therethrough into the tissue below. Thus, the
vaporisation is further accelerated. The passage of the radiated laser beam through
the carbonised layer advantageously performs a hemostasis effect in the tissue.
[0010] In the conventional probe, there is little vaporisation of the tissue directly due
to probe heat, rather, vaporisation is limited by the reaction within the tissue of
the laser energy as it penetrates into the tissue. In the present invention, by contrast,
vaporisation is not limited to heat generated by direct laser irradiation but includes
the heat of the probe tip as it is brought into physical contact with the tissue.
This heat, as noted, is generated by reason of the absorption of laser energy in the
coated surface of the probe tip.
[0011] In this connection, it is to be noted that while an output from the laser generating
unit of 40W or more is needed in the conventional probe for vaporization, 5 to 10W,
or in some cases, even 1 to 5W will suffice in the probe of the present invention
or effecting vaporization or incision.
[0012] The infrared absorbing material may be deposited on the smooth surface, but it is
preferably deposited in concaved portions of an uneven, roughened outer surface of
the probe. In the latter case, the infrared absorbing coating is generally protected
against being dislodged or detached and there is the further advantage that irregular
laser reflections within the concaved portions of the tip serve to enhance laser interaction
with the surface absorbant material thereby accelerating heat generation.
[0013] Since the fine particles of heat absorbing material may, notwithstanding the improved
adherence of this material to the roughened surface, become dislodged or possibly
subjected to oxidation, a protective coating of heat-resistant ceramic material is
preferably placed over the heat absorbing tip end of the probe. The coating, of course,
must be substantially transparent to the laser energy.
[0014] The present invention further provides a method for making a medical laser surgical
probe having a heat generating region thereon including the steps of taking a laser
probe and roughening the surface of the probe which defines the nominal laser radiation
region thereof; applying a coating of infrared absorbing material to the roughened
surface whereby said material collects in the uneven recesses defined in the roughened
surface region; and applying a protective laser transmissive coating over the infrared
absorbing coating.
[0015] It is therefore an object of the present invention to provide a medical probe which
is capable of performing tissue incision or vaporization at power levels lower than
required by conventional laser probe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Figure 1 is an elevation view, part in section, of the probe of the present invention
and a holding member therefor;
Figure 2 is an elevation view showing the probe of Figure 1 inserted into tissue;
Figure 3 is an enlarged sectional view of the probe end showing the heat generating
portion thereof;
Figure 4 is a further enlarged sectional view of the probe heat generating portion;
Figure 5 is an elevation view of an alternate embodiment of the probe according to
the preseent invention;
Figure 6 is an elevation view of another alternative embodiment of the probe according
to the present invention;
Figure 7 is a perspective view showing an incision of the retina using the probe of
Figure 6;
Figure 8 is an elevation view of a yet another alternative embodiment of the probe
of the present invention;
Figure 9 is a front elevation view of another embodiment of the probe of the according
to the present invention shown installed in the probe connector;
Figure 10 is a side elevational view of the probe shown in Figure 9;
Figure 11 is a front elevation view of the probe of Figure 10 as it appears apart
from its mounting connector; and
Figure 12 is an explanatory view of the force-cutting for incision using the probe
of Figures 9-11.
PREFERRED EMBODIMENT OF THE INVENTION
[0017] Figure 1 is a longitudinal sectional view of a probe 10 according to the present
invention which is mounted at the output end of a laser optical fiber 32. The fiber
is connected to a source of laser energy (not shown).
[0018] Probe 10 is fabricated from a laser transmissible material such as a natural or artificial
ceramic material, for example, a natural or artificial sapphire, quartz, or diamond.
Polymeric materials may also be employed. In the embodiment as illustrated, the probe
10 comprises a conically tapered main body portion 12 having, at the tip end thereof,
a heat generating portion 11 of semispherical shape and a mounting portion 14. The
main body portion 12 and the mounting portion 14 are formed integrally with each other
and a flange 16 is formed between the main body portion 12 and the mounting portion
14. The probe 10 is fitted in a cylindrical female connector 18 and fixed integrally
thereto by caulking the mating surfaces thereof or using a ceramic type adhesive between
the mating surfaces. The female connector 18 has, on the internal surface thereof,
a thread 20 which is adapted to mate with complementary threads 30 of a male connector
22 on the output end of the optical fiber 32. The female connector 18 has two holes
24 through the cylindrical connector wall which facilitate the passage of cooling
water W or other fluids therethrough. The two holes are circumferentially disposed
at angular spaces of 180° although only one of them is shown in Figure 1.
[0019] On the other hand, the male connector 22 is pressedly fitted into a flexible jacket
26 fabricated of, for example, Teflon (trademark). For this press fitting, the male
connector 22 has stepped portions 28 at the base portion of the male connector 22
by which the male connector 22 is firmly held by the jacket 26 so as to prevent the
former from being disengaged from the latter. As noted, male connector 22 is externally
threaded at 30 to mate with the internal thread 20 of the female connector 18.
[0020] An optical fiber 32 for transmitting laser energy is inserted into the male connector
22. The optical fiber 32 is disposed concentrically within the jacket 26, leaving
a gap 34 therebetween for supplying cooling water. Although the fiber 32 is closely
fitted in the male connector 18 at a portion adjacent to the stepped portion of the
male connector, the stepped portion 28 has for example two slits 28a formed circumferentially
at angular spaces of 180° for letting the cooling water W pass therethrough. A passage
36 for the cooling water W is further provided between the inner face of the tip end
portion of the male connector 22 and the optical fiber 32. Cooling water W is fed,
according to necessity, through the gap 34 then, in turn, through slit 28a, passage
36 and discharged through the opening 24 to cool the tissue to be treated.
[0021] A laser generating unit (not shown) is optically coupled to the input end of fiber
32. A 40 watt laser is common although tissue vaporization can be effected using probes
of the present invention with laser powers in the order of 10 watts or less. The laser
beam from the laser generating unit is guided through the optical fiber 32 and coupled
from the output end thereof to the probe 10 through the base end face 38 thereof.
The laser energy is then radiated from the outer face of the probe tip or, as discussed
in more detail below, absorbed by the material coating the probe tip.
[0022] Figure 2 illustrates the dispersion and diffusion of laser energy when the probe
of the present invention is employed. As the main body portion 12 of the probe 10
is formed in a conically tapered shape, some of laser energy may leak from the tapered
face but the majority of the laser energy is reflected from the tapered face towards
the tip end thereof. Thus, the laser beam is effectively focused and concentrated
at the tip region 11 from which point the laser energy is either radiated or absorbed.
Region 11 defines the heat generating portion of probe 10.
[0023] The outer surface of the heat generating portion 11 of the probe is frosted or roughened
as shown in Figures 3 and 4 thereby forming an uneven and irregular contour defining
apertures or recesses therein having diameter and depth of 1 to 100 um, preferably
10 to 60 um. The frosting or roughening process is preferably carried out by use of
a computer controlled grinding wheel. More specifically, the probe undergoing surface
treatment is rotated and then brought into contact with a diamond grindstone. The
grindstone traces the unroughened contour of the probe, commencing from the tip of
the probe, as far rearward along the conical surface as desired to define the heat
generating portion 11 thereof. The computer controls, in a conventional manner, the
position and speed of travel of the grindstone. In one preferred arrangement, a grindstone
having particles of between 10 to 20 um is utilized while the grindstone is moved
along the probe between 3 and 6 mm/second. This results in a roughened surface contour
having approximately 10um recesses therein. Of course, other methods may be employed
to roughen the probe surface.
[0024] In the event that the depth of the recesses defining the roughened surface are too
small, the amount of the infrared absorbing material held therein is correspondingly
small thereby rendering the heat generating effect insufficient. Conversely, if the
surface roughening is too large, excessive heat absorbing material will be retained
with a corresponding decrease in the direct laser irradiation of the tissue and an
increase in probe tip heating. It is preferable to roughen the tip surface within
the limits set out above to maintain a proper balance between direct laser irradiation
and indirect heating caused by laser absorption at the probe tip.
[0025] Referring to Figure 4, the infrared absorbing material 112 is received and held in
the concaved portions 111 formed by the frosting or roughening process. Various compositions
may be used for the infrared absorbing material including MnO
2, Fe
3O
4, CoO, and Cr
2O
3. The preferred material is manganese dioxide due to its high melting point. Graphite
or carbon may also be utilized although these materials may exhibit oxidation. The
particle size of the infrared absorbing material is small, typically 10um or less.
To attach the infrared absorbing material to the frosted or roughened surface of the
main body portion 12 of the probe 10, the tip end portion of the main body portion
12 is dipped in a suspension of the infrared absorbing material. As a dispersion medium,
there can be suitably used water or alcohol due to their rapid drying rate. The density
of the infrared absorbing material may be selected by controlling the concentration
of the dispersion and/or the temperature of the dispersion for obtaining desired heat
generation level. When homogeneous dispersion can not be obtained, or a surface active
agent is added to the dispersion.
[0026] Alternatively, cotton impregnated with the infrared absorbing material, or preferably
a dispersion of the infrared absorbing material, may be used to transfer the infrared
absorbing material to the frosted or roughened surface of the probe. More specifically,
1/2cc of powder is mixed in approximately 1cc of water. Dry cotton is dipped into
the powder suspension so that the cotton can absorb the powder evenly. Excess water
is squeezed from the cotton before the impregnated cotton is pressed and rubbed onto
the roughened tip surface. A clean piece of cotton is used to softly rub the probe
tip region to remove excess powder thereon.
[0027] The infrared absorbing material 112 deposited in the concaved portions 111 of the
frosted or roughened surface is preferably covered by a coating 113 to prevent damage
to the absorbing material during normal use.
[0028] Although the material of the coating 113 is not critical so long as it exhibits transmissivity
to laser energy as well as suitable heat resistance; an amorphous non-alkali glass
or a ceramic such as silica, polyalumina, is preferably utilized. The compound ZrO
2SiO
2 has been found to be quite satisfactory and is mixed with isopropyl alcohol to form
a solution (20% ZrO
2SiO
2) therewith. The protective overcoat solution may be applied in substantially the
same manner as that described for the absorbing powder. Cotton is dipped into the
solution and lightly painted over the powdered tip area. The probe is permitted to
dry at room temperature for approximately 30 minutes, then, baked at 150°C for another
30 minutes. The above described overcoating steps are repeated until a thickness of
between 1 um and 5 um is achieved.
[0029] Figure 4 illustrates the action of the roughened, impregnated tip on an incident
laser beam as the beam attempts to pass through the tip region. As the laser beam
enters the heat generating portion 11, the laser energy is irregularly reflected from
both the randomly spaced infrared absorbing particles 112 and the surface of the concave
portions 111 of the probe tip. The laser energy is partially attenuated by the heat
absorbing material with the remainder utlimately being radiated from the tip. This
laser energy irradiates and penetrates the adjacent tissue in the conventional manner.
That portion of the laser energy absorbed is converted to heat which, in turn, raises
the temperature of the heat generating tip portion 11. Although the precise temperature
of this tip region depends upon the density of the infrared absorbing material adhering
to the surface of the heat generating portion and the laser power, temperatures between
about 500 and 700°C are typical for probes prepared as set forth herein. It will be
appreciated that such elevated probe tip temperatures substantially accelerate the
vaporization of the tissue contacted by the probe.
[0030] Although the heat generating portion 11 is shown only at the semispherical portion
of the tip end of the main body 12 in the foregoing embodiment, it may be provided
at other parts of the tapered portion or along its entire length as shown at 11 in
Figure 6. In this case, the tapered portion is also frosted or roughened so that the
percentage of the laser beam reaching the probe tip is reduced while the precentage
of overall probe laser radiation is increased. The modified probe 10A of Figure 6
is suitably used, for example, for selectively effecting incision of retina 52 (Figure
7) without making incision of choroidea 51 due to the vaporization effect of heat
generation at the tapered portion when the retina 52 is detached from the choroidea
51 of the eyeground.
[0031] The probe may alternatively have a round shape as shown in Figure 8. Probe 10B has
a semispherical end provided with the heat absorbing material, as discussed above,
at 11. This probe is suitably imployed for vaporization and incision of, for example,
a constricted part of an esophagus.
[0032] The configuration of the probe may alternatively be such that the opposite sides
of the tip end of a cylinder are bevelled thereby defining a wedge-shaped end as shown
in Figures 9 to 12. This type of probe 10C may be used in such a manner that it is
strongly pressed against the tissue M to make force-cutting for effecting the incision
of the tissue M.
[0033] The length of the heat generating portion 11 of the probe 10 as illustrated in Figures
1 to 10 may be suitably determined according to the injection depth of the probe into
the tissue M and it may in general be within a range of from 1.0 to 7.0 mm. Although
the tip end of the heat generating portion 11 is not always required to be in semispherical
shape, a pointed end of the heat generating portion would possibly be broken and therefore
the tip end of the heat generating portion is preferably be rounded. The flange 16
as described before functions as an abutment or stop for positioning of the probe
10 in the tissue M when the probe 10 is injected into the tissue M until the forward
end face of the projected flange 16 abuts against the tissue M. However, the flange
16 may of course be omitted.
[0034] Figure 13 illustrates a further form of the probe in which the heat generating portion
11 is extended to the intermediate portion of the taper. This type of probe 10D may
be fitted to a surgical contact scalpel.
1. A medical laser probe (10) for conveying energy from the output end of an optical
laser waveguide (32) to a tissue undergoing laser treatment, the probe comprising
laser transmissive material having a laser energy input region for receiving laser
energy from the optical waveguide and a laser energy radiation surface (11), the laser
energy from the input region being propagated through the probe transmissive material
to be incident on the probe radiation surface, characterised in that an infrared absorbing
coating (112) is applied to and conforming with the laser energy radiation surface
for converting a predetermined percentage of the laser energy incident thereon into
heat energy, whereby the increased temperature of the probe radiation surface will
enhance tissue vaporisation and whereby the laser energy entering the probe not converted
to heat energy by the infrared absorbing coating irradiates tissue adjacent the radiation
surface.
2. A medical laser probe as claimed in claim 1 characterised in that the infrared absorbing
coating (112) is covered by a coating (113) of a laser transmissive material.
3. A medical laser probe as claimed in claim 1 or 2, characterised in that the probe
radiating surface (11) has an irregular and uneven contour defining concave recesses
(111) for irregularly refracting and reflecting the laser energy incident thereon
and for receiving the infrared absorbing coating in said concave recesses.
4. A medical laser probe as claimed in claim 3, characterised in that the concave recesses
(111) defining the uneven surface contours range between 1 and 100 microns.
5. A medical laser probe as claimed in any one of claims 1 to 4, characterised in that
said infrared absorbing coating (112) is selected from graphite, carbon, clay and
titanium oxide, magnesium oxide and iron oxide.
6. A medical laser probe as claimed in any one of claims 1 to 5, characterised in that
the infrared absorbing coating (112) is a powder material having granule sizes less
than about 10 microns.
7. A medical laser probe as claimed in any one of claims 2 to 6, characterised in that
the laser transmissive coating (113) is made of amorphous non-alkali glass.
8. A medical laser probe as claimed in any one of claims 2 to 6, characterised in that
the laser transmissive coating (113) is ZrO2 SiO2.
9. A process for making a medical laser surgical probe having a heat generating region
thereon including the steps of taking a laser probe (10) according to claim 1 and
roughening the surface of the probe (11) which defines the nominal laser radiation
region thereof; applying a coating of infrared absorbing material (112) to the roughened
surface whereby said material collects in the uneven recesses defined in the roughened
surface region; and applying a protective laser transmissive coating (113) over the
infrared absorbing coating.
10. A process as claimed in claim 9, characterised by the steps including the steps of
taking the laser probe (10) and grinding the surface (11) of the probe which defines
the nominal laser radiation region thereof to create an irregular, uneven contour
having concave (111) recesses of between 1 and 100 microns; taking a powder of laser
absorbing material (112) comprising particles of less than 10 microns in diameter
and preparing a suspension thereof; dipping an applicator into the suspension and
stroking the applicator with the infrared absorbing material therein against the uneven
probe surface contour thereby depositing absorbing material in the concave recesses
defined therein.
11. A process as claimed in claim 10 characterised by the further steps of preparing an
alcohol solution containing a soluble ceramic amorphous compound; applying the solution
over the uneven surface contour containing the laser absorbing material and drying
the laser probe to remove the alcohol therefrom.
1. Medizinische Lasersonde (10) zum Übermitteln von Energie vom Auslaßende eines optischen
Laserlichtwellenleiters (32) zu einem mit Laser zu behandelnden Gewebe, wobei die
Sonde: laserdurchlässiges Material mit einem Laserenergieeinlaßbereich zum Aufnehmen
der Laserenergie vom optischen Wellenleiter und eine Laserenergieabstrahlungsoberfläche
(11) aufweist, wobei die Laserenergie vom Einlaßbereich durch die Sonde aus durchlässigem
Material geführt wird, um auf die Sondenabstrahlungsoberfläche aufzutreffen, dadurch
gekennzeichnet, daß eine infrarotabsorbierende Beschichtung (112) entsprechend der
Laserenergieabstrahlungsoberfläche zum Umwandeln eines vorbestimmten Prozentsatzes
der darauf auftreffenden Laserenergie in Wärmeenergie aufgebracht ist, wobei die erhöhte
Temperatur der Sondenstrahlungsoberfläche die Gewebeverdampfung erhöhen wird und wodurch
die in die Sonde eingebrachte Laserenergie, die nicht durch die infrarotabsorbierende
Schicht in Wärmeenergie umgewandelt wird, Gewebe benachbart zur Abstrahlungsoberfläche
bestrahlt.
2. Medizinische Lasersonde nach Anspruch 1, dadurch gekennzeichnet, daß die infrarotabsorbierende
Beschichtung (112) mit einer Schicht (113) eines laserdurchlässigen Materials bedeckt
ist.
3. Medizinische Lasersonde nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Abstrahlungsoberfläche
der Sonde (11) einen unregelmäßigen und unebenen Umriß besitzt, der konkave Vertiefungen
(111) zur irregulären Refraktion und Reflexion der auftreffenden Laserenergie und
zum Aufnehmen der infrarotabsorbierenden Beschichtung in diesen konkaven Vertiefungen
bestimmt.
4. Medizinische Lasersonde nach Anspruch 3, dadurch gekennzeichnet, daß die konkaven
Vertiefungen (111), die den unebenen Oberflächenumriß bestimmen, zwischen 1 und 100
µm liegen.
5. Medizinische Lasersonde nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet,
daß die infrarotabsorbierende Beschichtung (112) aus Graphit, Kohlenstoff, Tonerde
und Titanoxid, Magnesiumoxid und Eisenoxid ausgewählt ist.
6. Medizinische Lasersonde nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet,
daß die infrarotabsorbierende Beschichtung (112) ein Pulvermaterial mit Korngrößen
unter 10 µ ist.
7. Medizinische Lasersonde nach einem der Ansprüche 2 bis 6, dadurch gekennzeichnet,
daß die laserdurchlässige Beschichtung (113) aus einem amorphen alkalifreien Glas
hergestellt ist.
8. Medizinische Lasersonde nach einem der Ansprüche 2 bis 6, dadurch gekennzeichnet,
daß die laserdurchlässige Beschichtung (113) ZrO2SiO2 ist.
9. Verfahren zum Herstellen einer chirurgischen medizinischen Lasersonde, die einen wärmeentwickelnden
Bereich darauf besitzt, das die Schritte beinhaltet:
Vorlegen einer Lasersonde (10) nach Anspruch 1 und Aufrauhen der Oberfläche der Sonde
(11), wodurch der nominale Laserabstrahlungsbereich derselben definiert wird;
Aufbringen einer Schicht eines infrarotabsorbierenden Materials (112) auf die aufgerauhte
Oberfläche, wobei das Material sich in den unebenen Vertiefungen, die im aufgerauhten
Oberflächenbereich enthalten sind, sammeln; und
Aufbringen einer schützenden laserdurchlässigen Schicht (113) über der infrarotabsorbierenden
Schicht.
10. Verfahren nach Anspruch 9, gekennzeichnet durch die Schritte, die die Schritte:
Vorlegen der Lasersonde (10) und Schleifen der Sondenoberfläche (11) der Sonde, die
den nominalen Laserabstrahlungsbereich desselben definiert, um einen irregulären,
unebenen Umriß mit konkaven Vertiefungen (111) von zwischen 1 und 100 µm zu bilden;
Vorlegen eines Pulvers aus laserabsorbierendem Material (112), das Partikel eines
Durchmessers von weniger als 10 µ aufweist und Herstellen einer Suspension davon;
Eintauchen eines Applikators in die Suspension; und
Bestreichen des unebenen Sondenoberflächenumrisses mit dem Applikator mit dem infrarotabsorbierenden
Material, um dabei absorbierendes Material in den darin definierten konkaven Vertiefungen
abzulagern.
11. Verfahren nach Anspruch 10, gekennzeichnet durch die weiteren Schritte:
Herstellen einer alkoholischen Lösung, die eine lösliche amorphe keramische Verbindung
enthält;
Auftragen der Lösung auf den unebenen Oberflächenumriß, (die das laserabsorbierende
Material enthält) und Trocknen der Lasersonde zum Entfernen des Alkohols.
1. Sonde laser à usage médical (10) pour transporter de l'énergie à partir d'une extrémité
émettrice d'un guide d'onde laser optique (32) vers un tissu soumis à un traitement
laser, sonde comprenant un matériau conducteur de rayonnement laser comportant une
région réceptrice d'énergie laser pour recevoir de l'énergie laser à partir du guide
d'onde optique et une surface rayonnante d'énergie laser (11), l'énergie laser provenant
de la région émettrice étant propagée à travers le matériau conducteur de la sonde
suivant un parcours incident à la surface rayonnante de la sonde, sonde caractérisée
en ce qu'un revêtement absorbant dans l'infrarouge (112) est appliqué de manière à
épouser la surface rayonnante d'énergie laser en vue de convertir un pourcentage prédéterminé
d'énergie laser incidente à la surface en énergie thermique, de sorte que l'élévation
de température de la surface rayonnante de la sonde favorise la vaporisation du tissu
et de sorte que l'énergie laser pénétrant dans la sonde non convertie en énergie thermique
par le revêtement absorbant dans l'infrarouge irradie le tissu adjacent à la surface
rayonnante.
2. Sonde laser à usage médical selon la revendication 1, caractérisée en ce que le revêtement
absorbant dans l'infrarouge (112) est recouvert d'un revêtement (113) de matériau
conducteur de rayonnement laser.
3. Sonde laser à usage médical selon la revendication 1 ou 2, caractérisée en ce que
la surface rayonnante de la sonde (11) présente un contour irrégulier et non uniforme
décrivant des replis concaves (111) destiné à réfracter et à réfléchir l'énergie laser
incidente à la surface et à recevoir le revêtement absorbant dans l'infrarouge dans
lesdits replis concaves.
4. Sonde laser à usage médical selon la revendication 3, caractérisée en ce que les replis
concaves (111) que décrit la surface non uniforme mesurent de 1 à 100 µm.
5. Sonde laser à usage médical selon l'une quelconque des revendications 1 à 4, caractérisée
en ce que ledit revêtement absorbant dans l'infrarouge (112) est choisi parmi le graphite,
le carbone, l'argile et l'oxyde de titane, l'oxyde de magnésium et l'oxyde de fer.
6. Sonde laser à usage médical selon l'une quelconque des revendications 1 à 5, caractérisée
en ce que le revêtement absorbant dans l'infrarouge (112) est un matériau pulvérulent
de granulométrie inférieure à 10 µm environ.
7. Sonde laser à usage médical selon l'une quelconque des revendications 2 à 5, caractérisée
en ce que le revêtement conducteur de rayonnement laser (113) est fabriqué en verre
amorphe non alcalin.
8. Sonde laser à usage médical selon l'une quelconque des revendications 2 à 6, caractérisée
en ce que le revêtement conducteur de rayonnement laser (113) est en ZrO2 - SiO2.
9. Procédé de fabrication d'une sonde laser chirurgicale à usage médical dotée en surface
d'une région génératrice de chaleur comprenant les étapes consistant à obtenir une
sonde laser (10) selon la revendication 1 et à dépolir la surface de la sonde (11)
qui définit la région rayonnante d'énergie laser nominale; à appliquer un revêtement
de matériau absorbant dans l'infrarouge (112) à la surface dépolie de manière à ce
que ledit matériau s'accumule dans les replis non uniformes que décrit la région de
surface dépolie, et à appliquer un revêtement protecteur conducteur de rayonnement
laser (113) sur le revêtement absorbant dans l'infrarouge.
10. Procédé selon la revendication 9, caractérisé en ce qu'il comporte les étapes consistant
à obtenir la sonde laser (10) et à dépolir la surface (11) de la sonde qui définit
la région rayonnante d'énergie laser nominale en vue de former un contour irrégulier
non uniforme présentant des replis concaves (111) mesurant de 1 à 100 µm; à obtenir
une poudre de matériau absorbant de rayonnement laser (112) comprenant des particules
de diamètre inférieur à 10 µm pour en préparer une suspension; à tremper un applicateur
dans la suspension et à frotter l'applicateur contenant le matériau absorbant dans
l'infrarouge contre la surface de la sonde de contour non uniforme de manière à déposer
le matériau absorbant dans les replis concaves que décrit la surface.
11. Procédé selon la revendication 10, caractérisé en ce qu'il comporte en outre les étapes
de préparation d'une solution alcoolique contenant un composé céramique amorphe soluble;
d'application de la solution contenant le matériau absorbant de rayonnement laser
sur la surface de contour non uniforme et de séchage de la sonde laser afin d'en éliminer
l'alcool.